In total, he has won eight medals in major international tournaments, including his first career gold from the 2006 FINA World Short Course Championships in Shanghai, China.

While residing in the United States, Polyakov is a five-time SEC champion, a double NCAA titleholder, and a two-time gold medalist at the national championships.

He was put in a national program for elite swimmers, and was forced to undergo a rigorous training that left him fatigued and mentally ill.[3] In June 1999, Polyakov came to the United States under the guidance of his mother Galina, concerned about her son's lifetime goals.

Polyakov almost gave up his sporting career before he decided to leave Eastern Europe: "At the time I left Russia I was sick mentally, I didn't want to go through another hard practice.

"[3] During his first trip to the United States, Polyakov met Michael Goldenberg, a former Russian water polo player working as a top-ranked official and coach.

He attended Saint Thomas Aquinas High School in Fort Lauderdale, graduating in 2002, and swam for the Coral Springs Swim Club under four-time Olympic coach Michael Lohberg.

[5] In his senior season, Polyakov was among the top swimmers to be selected by the College Sports Information Directors of America, in honor of the Men's ESPN The Magazine Academic At-Large All-Americans of the Year.

[24] Two weeks later, at the 2005 Summer Universiade in Izmir, Turkey, Polyakov earned a silver medal in the 200 m breaststroke at 2:12.69, just 0.34 seconds off a leading time set by Poland's Sławomir Kuczko.

[31] In early 2007, Polyakov decided to skip from the World Championships to focus on his senior season for the Alabama Crimson Tide, handing his teammate Yevgeniy Ryzhkov a slot.

In his first event, 50 m breaststroke, Polyakov shared a three-way tie with Iran's Mohammad Alirezaei and Japan's top medal contender Kosuke Kitajima for fourth place in 28.15.

[42] Polyakov also captured a bronze as a member of the Kazakhstan team in the 4 × 100 m medley relay (3:40.55), following China's disqualification for an early takeoff on the breaststroke leg.

[46] Unlike his two previous Games, he posted an Olympic selection time (formerly a B-cut) of 1:01.48 from the USA Swimming Grand Prix in Indianapolis, Indiana.